The stain on your underwear as a result of sharting, sometimes permeating to the outer layers of your clothing. Usually accompanied by a putrid odour. Biohazardous.
I thought I just farted, then I checked my underwear and saw a huge krassenstein.
I could smell the krassenstein as he took off his trousers.
As I walked into the room, the dog ran straight to me and nuzzled my krassenstein
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi